170 REPORTS ON THE STATE OF SCIENCE.—1914. 
_ Some of the yellow mice were mated with albinos, as I wished to 
discover and eliminate strains carrying albinism. These matings were 
thus incidental, but may nevertheless be put on record as follows :— 
: Choco- | Silver- 
Black, |Blue, 2.e., . 5 
Yellow X Albino | Yellow |7.e.,dense} dilute tie BiG foveee Albino Total 
| black black chocolate |chocolate 
é x — 2 — — — 2 4 
ee OL — 1 — — — 1 2 
aN qe 1 2 — —- | — 4 7 
Ge aX ace 2 — ee er 5 7 
De mS, — | 1 — —- | — 1 2 
O ex) a i ee 2 1 Fe Fi ore 1 6 
3 10 1 — — 14 28 
ou x he 2 2 = 2 — — 6 
Oo axe 2 4 2 == — — — 6 
Grex = — a 2 — — | 2 
an exis? 1 1 = 3 —_ — | 5 
Bee ae. 3 2 — 2 -—— — | 7 
Bex. AO 1 1 1 _ — | 3 
Cox, <2 1 4 — — — — | 5 
ox Se 4 1 — — — — | 5 
oo xe 2 —- |; — 2 — — 4 
Om Cf 2 | — — — | 3 
er oer & 4 ); — | = 1 — — | 5 
On 2 2 |; — tees 3 — — | 5 
oe = _ a 1 — — | 1 
Ps gues ig 5 =p — —- | — } 5 
OE AG 2 is | 1 — 1 el 6 
Oars == aa 1 2 = eee 
OFESS ac | 4 3 — — = Sl i 
Oy deh 3 2 — oo — — | 5 
OSE) eh 2 1 — — — aa 3 
Observed | 45 33 3 19: sey 14, 21, ee 
SS | 
56 | 
Calculated 50:5 50:5 
It does not appear necessary to discuss the above matings 
individually, but one notes :— 
(a) In those litters where albinos are present the proportions of 
coloured and albino young agree with expectation. Equality is ex- 
pected, the numbers are 14:14. 
(b) Among the coloured offspring 45 are yellow and 56 other colour, 
expectation being equality since all the yellow parents are known to be 
heterozygous either from their parentage or from some other mating. 
General Resiulls of the Present Experiments on the Heredily of Yellow 
Coat Colour in Mice. 
Firstly, to confirm in a different strain of mice the evidence that 
yellow mice occur only in the heterozygous condition; and secondly, 
to support the view that in the mating yellow x yellow, zygotes of the 
formula Y Y are actually formed, but are abortive. 
